Myanmar has shown marked improvements in its ranking, jumping from 172nd last year to 157th spot this year.

Indonesia's ranking has moved from 118th position to 114th, with Mr Leonard saying the country is making an attempt to clean up.

"The current Indonesian government has made great efforts to improve their anti-corruption techniques but it's a long slow process, particularly in a democracy," he said.

Thailand and Sri Lanka were two other countries that have dropped in their rankings this year to 102nd and 91st position respectively.

At the other end of the scale, Afghanistan, North Korea and Somalia were the worst performers.

Measuring corruption

The rankings were put together after going through a four-stage process, using data from 12 different organisations that measure public sectors around the world.

"For any country to qualify to be in the survey, there has to be at least three credible surveys and that's why many of our smaller neighbours in the Pacific region like Fiji are not in the survey because they're not sufficient, credible sources available to us."

Transparency International's annual list is the most widely used indicator of sleaze in political parties, police, justice systems and civil services.

It gives countries a score between 0-100, where 0 means a country's public sector is considered highly corrupt and 100 means it is regarded as very clean.

Mr Leonard also expressed concerns about the Pacific which ranked 144 out of 177 countries and had among the lowest scores.

"It's 25 out of 100... that's disturbing and a worry particularly as the stakes get higher and higher in Papua New Guinea with natural gas developments there," he said.